TW202027211A - Regeneration method of electrostatic chuck and electrostatic chuck - Google Patents

Abstract

Provided are an electrostatic chuck regenerating method and an electrostatic chuck, which can reduce the processing amount. The electrostatic chuck regenerating method includes the following processes of: providing the electrostatic chuck having a concave portion and a convex portion protruding from the bottom of the concave portion; forming a first mask covering the concave portion except the convex portion; cutting the surface of the electrostatic chuck by using the first mask; removing the first mask; forming a second mask at the bottom in a position different from the position of the convex portion; cutting the surface of the electrostatic chuck by using the second mask; and removing the second mask.

Description

Regeneration method of electrostatic chuck and electrostatic chuck

The invention relates to a regeneration method of an electrostatic chuck and an electrostatic chuck.

In the plasma processing device, an electrostatic chuck for electrostatically adsorbing the substrate in the processing chamber is provided. When the electrostatic chuck is dry cleaned without wafers, it is equivalent to being exposed to the process gas in the processing chamber, so that the surface of the electrostatic chuck is deteriorated and the adsorption performance is reduced.

Patent Document 1 discloses a method of regenerating an electrostatic chuck, which removes the flange portion and the support portion of the suction surface of the chuck body across a specific thickness to form a flat surface, and again convex to the flat surface Margin and support. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-162084

[The problem to be solved by the invention]

In one aspect, the present invention provides an electrostatic chuck regeneration method and an electrostatic chuck that can reduce the processing amount. [Technical means to solve the problem]

In order to solve the above-mentioned problems, according to one aspect, there is provided a method for regenerating an electrostatic chuck, which includes the steps of providing the electrostatic chuck having a concave portion and a convex portion protruding from the bottom surface of the concave portion; and forming a covering and removing the convex portion Step of the first mask of the concave portion other than the above; the step of cutting off the surface of the electrostatic chuck through the first mask; the step of removing the first mask; in a position different from the position of the convex portion The step of forming a second mask on the bottom surface; the step of cutting off the surface of the electrostatic chuck through the second mask; and the step of removing the second mask. [Effects of Invention]

According to one aspect, an electrostatic chuck regeneration method and an electrostatic chuck that can reduce the amount of processing can be provided.

Hereinafter, a mode for implementing the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same symbols, and repeated descriptions may be omitted.

≪Regeneration method of electrostatic chuck 100 in one embodiment≫ The regeneration method of the electrostatic chuck 100 according to an embodiment will be described using FIGS. 1 to 2. 1 and 2 are diagrams illustrating a regeneration method of the electrostatic chuck 100 according to an embodiment.

First, the structure of the electrostatic chuck 100 will be described. FIG. 1(a) is a cross-sectional view of an example of the electrostatic chuck 100. FIG. 1(b) is a top view of an example of the electrostatic chuck 100. In addition, FIG. 1(a) is a view with the substrate mounting surface as the top, and FIG. 1(b) is a view viewed from the direction of the substrate mounting surface.

The electrostatic chuck 100 has a substrate placing surface formed on the upper surface of the base 150. A flange 110, a concave portion 120 having a bottom surface 130, and a convex portion 140 are formed on the substrate placement surface. The flange 110 and the convex portion 140 are formed integrally with the base 150. In addition, the base 150, the flange 110, and the convex portion 140 are formed of, for example, a dielectric such as alumina ceramic.

The flange 110 is a ring-shaped part provided on the outer periphery of the substrate placement surface of the electrostatic chuck 100. The recess 120 is an internal space surrounded by the ring-shaped flange 110. In addition, the recess 120 has a bottom surface 130. The convex portion 140 is a columnar portion erected from the bottom surface 130. In addition, in FIGS. 1 and 2, it is schematically shown that two protrusions 140 are formed on the substrate mounting surface of the electrostatic chuck 100, but the shape, number, arrangement, etc. of the protrusions 140 are not limited thereto.

When a substrate (not shown) is placed on the electrostatic chuck 100, the outer peripheral edge of the back surface of the substrate is in surface contact with the ring-shaped flange 110. In addition, a plurality of convex portions 140 are provided in the concave portion 120, and the upper surface of the convex portion 140 is in contact with and supported by the back surface of the substrate. In addition, the base 150 of the electrostatic chuck 100 is embedded with internal electrodes (not shown). By applying voltage to the internal electrodes, the substrate placed on the substrate placement surface is sucked.

In addition, the electrostatic chuck 100 is, for example, disposed in a processing chamber of a plasma processing device. Therefore, the electrostatic chuck 100 is exposed to the process gas used for processing the substrate, etc., which deteriorates the surface of the electrostatic chuck 100. Due to the deterioration of the surface, the performance of the electrostatic chuck 100 for adsorbing the substrate is reduced.

In the method for regenerating the electrostatic chuck 100 of one embodiment, the adsorption performance of the electrostatic chuck 100 is regenerated by performing a process of cutting off the surface of the electrostatic chuck 100. Hereinafter, a method of regenerating the electrostatic chuck 100 according to an embodiment will be described.

＜Provide steps＞ In the providing step, the flange 110 provided on the outer peripheral edge as shown in Figs. 1(a) and 1(b), the recess 120 surrounded by the flange 110, and the protrusion protruding from the bottom surface 130 of the recess 120 are provided. The electrostatic chuck 100 of the part 140 is provided to a processing device that performs regeneration treatment of the electrostatic chuck 100.

＜Step 1＞ Fig. 1(c) is a cross-sectional view of an example of the electrostatic chuck 100 in the first step. Fig. 1(d) is a top view of an example of the electrostatic chuck 100 in the first step. In addition, in FIG. 1(d) and the following FIG. 1(f), the first mask 200 in a plan view is shaded and illustrated.

In the first step, a first mask 200 is formed on the upper surface (substrate mounting surface) of the electrostatic chuck 100 to cover the flange 110 and the recess 120 except for the protrusion 140. For example, the first mask 200 covering the bottom surface 130 of the recess 120 is formed by filling the recess 120 with a mask material. At this time, the upper surface of the convex portion 140 is exposed from the first mask 200. In addition, for example, the first mask 200 covering the upper surface of the flange 110 is formed by applying a mask material to the upper surface of the flange 110. Furthermore, when the mask material is applied to the upper surface of the flange 110, the mask material may also be exposed from the side of the electrostatic chuck 100. Furthermore, as the mask in the first step, for example, a mask formed by curing a liquid resin can be used.

＜Step 2＞ Fig. 1(e) is a cross-sectional view of an example of the electrostatic chuck 100 in the second step. FIG. 1(f) is a top view of an example of the electrostatic chuck 100 in the second step.

In the second step, the surface of the electrostatic chuck 100 is removed through the first mask 200. Furthermore, the removal processing is, for example, blast processing, grinding processing, and laser processing. For example, in the blasting process, the projection material is projected toward the upper surface of the electrostatic chuck 100 to grind the part not covered by the first mask 200. As described above, the flange 110 and the bottom surface 130 of the recess 120 are covered by the first mask 200. On the other hand, the upper surface of the convex portion 140 is not covered by the first mask 200. Therefore, the protrusion 140 is shaved and removed by removing the electrostatic chuck 100 in which the first mask 200 is formed. The convex part 140 is cut away to form the convex part mark 141.

Furthermore, in the second step, the height of the upper surface of the convex portion trace 141 is preferably approximately equal to the height of the bottom surface 130. In the example shown in FIG. 1(e), the upper surface of the convex portion trace 141 is higher than the bottom surface 130, and the convex portion trace 141 has a convex shape with respect to the bottom surface 130, but it is not limited to this. For example, the upper surface of the convex portion trace 141 may be lower than the bottom surface 130, and the convex portion trace 141 may have a concave shape with respect to the bottom surface 130.

＜Step 3＞ Fig. 1(g) is a cross-sectional view of an example of the electrostatic chuck 100 in the third step. FIG. 1(h) is a top view of an example of the electrostatic chuck 100 in the third step. In addition, in FIG. 1(h) and the following FIG. 2(b), the convex portion trace 141 in a plan view is shown with a broken line.

In the third step, the first mask 200 is removed from the electrostatic chuck 100. Furthermore, the method of removing the first mask 200 is not limited, and it may be removed by melting or peeling, for example.

<Step 4> FIG. 2(a) is a cross-sectional view of an example of the electrostatic chuck 100 in the fourth step. FIG. 2(b) is a top view of an example of the electrostatic chuck 100 in the fourth step. Furthermore, in FIG. 2(b) and the following FIG. 2(d), the second mask 300 in a plan view is shaded and illustrated.

In the fourth step, a second mask 300 is formed on the upper surface of the electrostatic chuck 100. The second mask 300 is formed on the bottom surface 130 at a position different from the position where the convex portion 140 (the convex portion trace 141) is provided. For example, the second mask 300 is formed by rotating the arrangement pattern of the convex portion 140 by a specific angle (90° in the example of FIG. 2(b)) with the center of the electrostatic chuck 100 as the center of rotation when viewed from above. In addition, as the mask of the fourth step, for example, a mask formed by curing a liquid resin may be used, or a sheet-shaped mask may be attached and formed without limitation.

<Step 5> FIG. 2(c) is a cross-sectional view of an example of the electrostatic chuck 100 in the fifth step. FIG. 2(d) is a top view of an example of the electrostatic chuck 100 in the fifth step.

In the fifth step, the surface of the electrostatic chuck 100 is removed through the second mask 300. Furthermore, the removal processing is, for example, blast processing, grinding processing, and laser processing. For example, in the blasting process, the projection material is projected toward the upper surface of the electrostatic chuck 100 to grind the part not covered by the second mask 300. As described above, a part of the bottom surface 130 is covered by the second mask 300. On the other hand, the flange 110, the remaining portion of the bottom surface 130, and the convex portion mark 141 are not covered by the second mask 300. Therefore, by removing the electrostatic chuck 100 in which the second mask 300 is formed, the remaining portions of the flange 110, the bottom surface 130, and the protrusion marks 141 are uniformly shaved off. Furthermore, the flange 110 after the processing in the fifth step is referred to as the flange 112, the processed bottom surface 130 is referred to as the bottom surface 132, and the processed convex portion mark 141 is referred to as the convex portion mark 142. Furthermore, in FIG. 2(d) and the following FIG. 2(f), the convex portion trace 142 in a plan view is shown by a dotted line. In addition, by removing processing, the height of the bottom surface 132 after processing is lower than the bottom surface 130 before processing, thereby forming a new convex portion 145 at the position where the second mask 300 is applied.

＜Step 6＞ FIG. 2(e) is a cross-sectional view of an example of the electrostatic chuck 100 in the sixth step. FIG. 2(f) is a top view of an example of the electrostatic chuck 100 in the sixth step.

In the sixth step, the second mask 300 is removed from the electrostatic chuck 100. The method of removing the second mask 300 can be, for example, finishing. In addition, finishing processing includes, for example, grinding processing, grinding processing, and laser processing. At this time, the upper surface of the processed flange 112 and the upper surface of the new convex portion 145 are also polished. Furthermore, the method of removing the second mask 300 is not limited to this, and it may be removed by melting or peeling, for example. In addition, when the second mask 300 is removed by melting, peeling, etc., a step may be added, that is, after the sixth step, the upper surface of the processed flange 112 and the new convex portion 145 The upper surface is polished.

＜Regeneration method of electrostatic chuck of reference example＞ Here, the regeneration method of the electrostatic chuck 500 of the reference example will be described using FIG. 3. FIG. 3 is a diagram illustrating the regeneration method of the electrostatic chuck 500 of the reference example. Furthermore, the structure of the electrostatic chuck before the regeneration process is the same as the structure shown in Fig. 1(a) and Fig. 1(b), and the repeated description is omitted.

Here, as a regeneration method of the electrostatic chuck, the following regeneration method is considered. That is, a mask is formed at the positions of the existing flange 110 and the convex portion 140, and the bottom surface 130 is shaved off by removing processing, thereby regenerating the static electricity. Chuck. However, it is technically difficult to accurately align the mask with the existing flange 110 and the convex portion 140. Therefore, in the regeneration method of the electrostatic chuck 500 of the reference example, after grinding the existing flange 110 or the protrusion 140, etc., the flange 510 or the protrusion 540, etc. are newly formed.

(Provide steps of reference example) In the step of providing the reference example, the flange 110 provided on the outer peripheral edge, the recess 120 surrounded by the flange 110, and the bottom surface 130 from the recess 120 shown in Figs. 1(a) and 1(b) The electrostatic chuck 100 of the protruding convex portion 140 is provided to a processing device that performs regeneration treatment of the electrostatic chuck 100.

(Step 1 of the reference example) FIG. 3(a) is a cross-sectional view of an example of the electrostatic chuck 500 in the first step of the reference example. FIG. 3(b) is a top view of an example of the electrostatic chuck 500 in the first step of the reference example.

In the first step of the reference example, the flange 110, the bottom surface 130 of the concave portion 120, and the convex portion 140 are removed by grinding. At this time, in order to ensure the parallelism of the upper surface 560 of the electrostatic chuck 500, the grinding amount is increased, and the amount of grinding is increased to the base 550 of the electrostatic chuck 500.

(Step 2 of the reference example) FIG. 3(c) is a cross-sectional view of an example of the electrostatic chuck 500 in the second step of the reference example. FIG. 3(d) is a top view of an example of the electrostatic chuck 500 in the second step of the reference example. Furthermore, in FIG. 3(d) and the following FIG. 3(f), the mask 600 in a plan view is shaded and illustrated.

In the second step of the reference example, a mask 600 is formed on the upper surface of the electrostatic chuck 100. The second mask 300 is formed at a position where a new flange and a new convex portion are provided.

(Step 3 of the reference example) FIG. 3(e) is a cross-sectional view of an example of the electrostatic chuck 500 in the third step of the reference example. FIG. 3(f) is a top view of an example of the electrostatic chuck 500 in the third step of the reference example.

In the third step of the reference example, the surface of the electrostatic chuck 500 on which the mask 600 is formed is subjected to removal processing (for example, spray processing). By removing the electrostatic chuck 500 formed with the mask 600, the part not covered by the mask 600 is evenly shaved off. Thereby, a groove 520 with a bottom surface 530 is formed. In addition, by removing processing, the height of the bottom surface 530 after processing is lower than the upper surface 560 before processing, thereby forming a new flange 510 and a new convex portion 540 at the position where the mask 600 is applied.

(Step 4 of the reference example) FIG. 3(g) is a cross-sectional view of an example of the electrostatic chuck 500 in the fourth step of the reference example. FIG. 3(h) is a top view of an example of the electrostatic chuck 500 in the fourth step of the reference example.

In the fourth step of the reference example, the mask 600 is removed from the electrostatic chuck 500.

Next, while comparing the regeneration method of the electrostatic chuck 500 of the reference example, the regeneration method of the electrostatic chuck 100 of an embodiment will be described.

According to the regeneration method of the electrostatic chuck 100 according to one embodiment, the deteriorated surface can be removed, so the adsorption performance of the electrostatic chuck 100 can be restored.

Here, as shown in the comparison between FIG. 2(e) and FIG. 3(g), the method of regenerating the electrostatic chuck 100 according to one embodiment can be processed in the height direction of the electrostatic chuck 100 in comparison with the reference example. The amount is reduced. This can shorten the processing time. In addition, compared with the reference example, the regeneration method of the electrostatic chuck 100 of one embodiment can leave more processing margin on the electrostatic chuck 100 side, so the number of regenerations of the electrostatic chuck 100 can be increased. Thus, the life of the electrostatic chuck 100 can be extended.

In addition, in the regeneration method of the electrostatic chuck 100 of one embodiment, the formation of the mask can be easily realized compared with the case where the mask is accurately formed at the positions of the existing flange 110 and the convex portion 140. That is, in the first step, it is possible to easily form a mask in a position other than the convex portion 140 by filling the concave portion 120 with a mask material and hardening it. In addition, in the fourth step, the second mask 300 is formed at a position on the bottom surface 130 that is different from the position where the protrusion 140 (protrusion mark 141) is provided, so strict position alignment is not required.

Furthermore, in the method of regenerating the electrostatic chuck 100 of one embodiment, the convex portion mark 142 remains on the new bottom surface 132. However, in the adsorption of the substrate by the electrostatic chuck 100, the influence of the flange 112 and the convex portion 145 is dominant, and the influence of whether the bottom surface 132 has unevenness is relatively small. Therefore, even if the protrusion marks 142 remain, the adsorption performance of the electrostatic chuck 100 can be ensured.

In addition, the time to perform the processing of the regeneration method of the electrostatic chuck 100 of an embodiment can be determined based on the operating time (for example, the high frequency application time) of the plasma processing apparatus, for example. In addition, it can also be determined based on the maintenance cycle of the plasma processing device.

In addition, a through hole (not shown) is provided on the bottom surface 130 of the electrostatic chuck 100. A pin that moves up and down is arranged in the through hole. With the pin lifting, the substrate placed on the substrate placement surface of the electrostatic chuck 100 can be lifted. In addition, by lowering the pins, a substrate supported by a plurality of pins can be placed on the substrate placing surface of the electrostatic chuck 100. Here, if the surface of the substrate mounting surface changes with time due to process gas or the like, the adsorption force between the substrate and the electrostatic chuck may increase with this. In this case, the driving torque value of the pin when the pin is raised after the substrate processing and the substrate is raised also rises. Therefore, it is also possible to determine the time to implement the regeneration treatment of the electrostatic chuck based on the driving torque value of the pin.

Above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-mentioned embodiment. Various changes, substitutions, etc. can be applied to the above embodiment without departing from the scope of the present invention. In addition, the features described separately can be combined as long as there is no technical contradiction.

It has been described that the electrostatic chuck 100 used in the regeneration method of the present invention is provided with the annular flange 110 on the outer periphery of the substrate placement surface, but it is not limited to this. The flange 110 may not be formed on the substrate mounting surface of the electrostatic chuck 100.

That is, in the electrostatic chuck of other embodiments, a substrate mounting surface is formed on the upper surface of the base 150. On the substrate placement surface, a concave portion 120 having a bottom surface 130 and a convex portion 140 are formed. The convex part 140 is formed integrally with the base 150. In addition, the base 150 and the protrusion 140 are formed of a dielectric material such as alumina ceramics, for example. Furthermore, the concave portion 120 is an internal space that is recessed compared to the convex portion 140 on the substrate placement surface. In addition, the recess 120 has a bottom surface 130. The convex portion 140 is a columnar portion erected from the bottom surface 130.

Regarding the electrostatic chuck of other embodiments, the electrostatic chuck of the other embodiment can be regenerated in the same way as the method of regenerating the electrostatic chuck 100 of one embodiment shown in FIGS. 1 to 2.

Furthermore, in the first step, on the upper surface (substrate mounting surface) of the electrostatic chuck of another embodiment, a first mask 200 covering the concave portion 120 other than the convex portion 140 is formed. For example, the first mask 200 covering the bottom surface 130 of the recess 120 is formed by filling the recess 120 with a mask material. At this time, the upper surface of the convex portion 140 is exposed from the first mask 200. Furthermore, when the mask material is applied to the bottom surface 130, the mask material may also be exposed from the side surface of the electrostatic chuck in other embodiments.

In the sixth step, the second mask 300 is removed from the electrostatic chuck of other embodiments. At this time, the upper surface of the new convex portion 145 is polished.

Except for this, it is the same as the regeneration method of the electrostatic chuck 100 of one embodiment, and the repeated description is omitted.

In this way, even in an electrostatic chuck without a flange, the adsorption performance can be restored in the same way as the regeneration method of the electrostatic chuck 100 of an embodiment.

The plasma processing device of the present invention is suitable for Capacitively Coupled Plasma (CCP), Inductively Coupled Plasma (ICP, inductively coupled plasma), Radial Line Slot Antenna (RLSA, Radial Line Slot Antenna), Electron Cyclotron Either Resonance Plasma (ECR, electron cyclotron resonance plasma), Helicon Wave Plasma (HWP, spiral wave plasma) can be applied.

In addition, the removal process used in the second step and the fifth step has been described, but the method of cutting off the parts not covered by the masks 200 and 300 is not limited to this, and other methods may be used. For example, plasma etching or the like can also be used.

100: Electrostatic chuck 110: flange 112: flange 120: recess 130: bottom 132: Bottom 140: convex 141: Convex Mark 142: Convex Mark 145: Convex 150: base 200: first mask 300: 2nd mask

Figure 1 (a) ~ (h) are diagrams illustrating an embodiment of the regeneration method of the electrostatic chuck. Figure 2 (a) ~ (f) are diagrams illustrating an embodiment of the regeneration method of the electrostatic chuck. Figure 3 (a) ~ (h) are diagrams illustrating the regeneration method of the electrostatic chuck of the reference example.

100: Electrostatic chuck

110: flange

120: recess

130: bottom

140: convex

141: Convex Mark

150: base

200: first mask

Claims (9)

A regeneration method of electrostatic chuck, which has: The step of providing the electrostatic chuck having a concave portion and a convex portion protruding from the bottom surface of the concave portion; The step of forming a first mask covering the above-mentioned recesses except for the above-mentioned convex parts; The step of cutting off the surface of the electrostatic chuck through the first mask; Steps of removing the above-mentioned first mask; A step of forming a second mask on the bottom surface at a position different from the position of the convex portion; The step of cutting off the surface of the electrostatic chuck through the second mask; and Steps to remove the second mask mentioned above. The method for regenerating an electrostatic chuck according to claim 1, wherein the step of cutting off the surface of the electrostatic chuck through the first mask is cutting off the convex portion. The method for regenerating an electrostatic chuck of claim 1 or 2, wherein the step of cutting off the surface of the electrostatic chuck through the second mask is to form a new convex portion at the position where the second mask is formed. The method for regenerating an electrostatic chuck according to claim 3, wherein the step of removing the second mask is polishing a new upper surface of the convex portion. The method for regenerating an electrostatic chuck according to any one of claims 1 to 3, wherein the electrostatic chuck provided in the step of providing the electrostatic chuck has a flange provided on the outer periphery of the electrostatic chuck, The step of forming the first mask is to form the first mask that covers the flange and the concave portion other than the convex portion. The method for regenerating an electrostatic chuck according to claim 5, wherein the step of removing the second mask is to polish a new upper surface of the convex portion and the upper surface of the flange. The method for regenerating an electrostatic chuck according to any one of claims 1 to 6, wherein the step of cutting off the surface of the electrostatic chuck uses spray processing. For example, the regeneration method of an electrostatic chuck according to any one of claims 1 to 7, which is based on the operation time of the plasma processing device equipped with the electrostatic chuck, the maintenance period of the plasma processing device, and the penetration of the electrostatic chuck The driving torque value of the pin moving up and down through the through hole determines the time to implement the regeneration process. An electrostatic chuck, which is regenerated by the method of regenerating the electrostatic chuck according to any one of claims 1 to 8.

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